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    <title>Document</title>
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    <script>
        /* 使用 * 打印三角形（用到循环嵌套）
        *
        **
        ***
        ****
        *****
        ******
        *******
        ********
        ********* */
       var m = '';
       for(var i = 0; i < 10; i++){
           for (var j = 2; j < i ; j++){
               m = m + ' * ';
               console.log( m );  
           } 
       }
    </script>
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